Protective device with separate end-of-life trip mechanism

Abstract

The present invention is directed to a protective wiring device for use in an electrical distribution system. The device includes a test facility includes a testing circuit configured to periodically generate at least one first test signal without execution of software instructions. A test monitoring circuit operates without execution of software instructions and is configured to effect an end-of-life detection state if the circuit interrupter fails to effect the tripped state in response to the electronics test failure state or in response to detecting a failure in the actuator assembly. An end-of-life circuit assembly is coupled to the test monitoring circuit, the end-of-life circuit assembly being configured to permanently decouple the plurality of line terminals from the plurality of load terminals in response to the end-of-life detection state.

What is claimed is: 
     
       1. A protective wiring device for use in an electrical distribution system, the device comprising:
 a plurality of line terminals including a line hot terminal and a line neutral terminal; 
 a plurality of load terminals including a plurality of feed-through load terminals and a plurality of receptacle load terminals; 
 a fault detection circuit coupled to the plurality of line terminals, the fault detection circuit being configured to provide a fault detection signal in response to detecting at least one predefined perturbation in the electrical distribution system; 
 an actuator assembly coupled to the fault detection circuit, the actuator assembly being configured to provide an actuator stimulus in response to the fault detection signal or in response to an electronics test failure state being effected; 
 a reset mechanism including a user-accessible button coupled to a mechanical linkage; 
 a circuit interrupter coupled to the actuator assembly and the reset mechanism, the circuit interrupter including four sets of interrupting contacts that are configured to provide electrical continuity between the plurality of line terminals and the plurality of load terminals in a reset state and configured to interrupt the electrical continuity in a tripped state, the reset state being effected when the circuit interrupter is engaged by the mechanical linkage in response to a user actuation of the user-accessible button, the tripped state being effected when the circuit interrupter is disengaged from the mechanical linkage in response to the actuator stimulus; 
 a test facility including a testing circuit configured to periodically generate at least one first test signal without execution of software instructions, the at least one first test signal being configured to induce a simulated fault corresponding to the at least one predefined perturbation, the test facility further comprising a manual test circuit being configured to generate a second test signal; 
 a test monitoring circuit operating without execution of software instructions and coupled to the fault detection circuit and the actuator assembly, the test monitoring circuit being configured to effect an electronics test verification state in response to receiving the fault detection signal corresponding to the first test signal and effect the electronics test failure state in response to not detecting the fault detection signal corresponding to the first test signal within a first predetermined period of time, the test monitoring circuit being configured to effect an end-of-life detection state if the circuit interrupter fails to effect the tripped state in response to the electronics test failure state or in response to detecting a failure in the actuator assembly; and 
 an end-of-life circuit assembly coupled to the test monitoring circuit, the end-of-life circuit assembly being configured to permanently decouple the plurality of line terminals from the plurality of load terminals in response to the end-of-life detection state. 
 
     
     
       2. The device of  claim 1 , wherein the second test signal is configured to induce the simulated fault corresponding to the at least one predefined perturbation. 
     
     
       3. The device of  claim 2 , wherein the actuator stimulus is configured to remove a mechanical barrier such that the circuit interrupter may effect the reset state. 
     
     
       4. The device of  claim 1 , wherein the second test signal is configured to energize a portion of the actuator assembly to generate the actuator stimulus without the fault detection signal being provided, the actuator stimulus being configured to remove a mechanical barrier such that the circuit interrupter may effect the reset state. 
     
     
       5. The device of  claim 4 , wherein the second test signal is effected when a source of AC power is properly connected to the plurality of line terminals and the second test signal is not effected when the source of AC power is not connected to the plurality of line terminals or is connected to the plurality of load terminals. 
     
     
       6. The device of  claim 1 , wherein the test monitoring circuit includes a timer circuit configured to measure elapsed time, the timer circuit generating the electronics test failure state when the first predetermined period of time has elapsed. 
     
     
       7. The device of  claim 6 , wherein the electronics test verification state resets the elapsed time measured by the timer circuit. 
     
     
       8. The device of  claim 1 , wherein the at least one first test signal is periodically generated as a function of line frequency. 
     
     
       9. The device of  claim 8 , wherein the simulated fault induced by the at least one first test signal is a simulated ground fault. 
     
     
       10. The device of  claim 1 , wherein the simulated fault induced by the at least one first test signal is a simulated grounded neutral condition. 
     
     
       11. The device of  claim 1 , wherein a portion of the four sets of interrupting contacts are configured to decouple the plurality of feed-through load terminals and the plurality of receptacle load terminals in the tripped state. 
     
     
       12. The device of  claim 1 , further comprising an auxiliary switch including at least one set of contacts that open in the tripped state and close in the reset state. 
     
     
       13. The device of  claim 12 , wherein the fault detection circuit is coupled to receive power from the plurality of line terminals by way of the auxiliary switch, the amount of power being made available to the fault detection circuit being substantially reduced when the auxiliary interrupting contacts are in the open position. 
     
     
       14. The device of  claim 13 , wherein the fault detection circuit receives power from the plurality of line terminals by way of an indicator circuit when the auxiliary switch is in the open position. 
     
     
       15. The device of  claim 14 , wherein the indicator circuit includes a trip indicator. 
     
     
       16. The device of  claim 1 , wherein the fault detection circuit is coupled to receive power from the plurality of line terminals, the amount of power being thus available to the fault detection circuit being substantially reduced in the tripped state. 
     
     
       17. The device of  claim 1 , wherein the end-of-life circuit assembly includes an end-of-life circuit coupled to an end of life interrupting mechanism that operates substantially independently from the circuit interrupter. 
     
     
       18. The device of  claim 17 , further including a coupling interface configured to selectively couple and decouple the end of life interrupting mechanism to the end-of-life circuit. 
     
     
       19. The device of  claim 18 , wherein the coupling interface includes at least one of the four sets of interrupting contacts. 
     
     
       20. The device of  claim 18 , wherein the coupling interface includes an electronic coupling circuit. 
     
     
       21. The device of  claim 1 , wherein the electronics test failure state is in response to an end of life condition includes an open component condition or a shorted component condition. 
     
     
       22. The device of  claim 1 , wherein the end of life circuit assembly is coupled to the plurality of line terminals by way of a solenoid. 
     
     
       23. The device of  claim 22 , wherein the end of life circuit assembly is coupled to the plurality of line terminals by a low pass filter comprising the inductance of the solenoid and a capacitor. 
     
     
       24. The device of  claim 1 , wherein the electronics test failure state indicates that at least one of a first subset of end of life conditions has occurred, and wherein the end-of-life detection state may indicate that at least one of a second subset of end of life conditions has occurred. 
     
     
       25. The device of  claim 24 , wherein the first subset includes a sensor end-of-life condition, a fault detection circuit end-of-life condition, an open circuit condition, or a short circuit condition. 
     
     
       26. The device of  claim 24 , wherein the second subset includes an open circuited trip solenoid end of life condition, an open SCR end of life condition, or an end of life condition occurring in the end-of-life circuit assembly. 
     
     
       27. The device of  claim 26 , wherein the end-of-life detection state is generated in response to the second test signal. 
     
     
       28. The device of  claim 1 , wherein the actuator assembly includes a first SCR coupled to the trip solenoid and the end-of-life circuit assembly includes a second SCR coupled to the trip solenoid. 
     
     
       29. The device of  claim 1 , wherein the end-of-life circuit assembly includes an end-of-life indicator, the end-of-life indicator being configured to generate a user-perceivable end-of-life signal when the end-of-life circuit assembly permanently decouples the plurality of line terminals from the plurality of load terminals. 
     
     
       30. The device of  claim 29 , wherein the user-perceivable end-of-life signal is visible, audible or both. 
     
     
       31. The device of  claim 1 , wherein the actuator assembly includes a solenoid or an electronic switch device.